THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

CAROL COSTELLO, CNN CORRESPONDENT: Thanks a lot, Kitty. I am Carol Costello in New York with a quick check of the day's top stories. Just in time for the official start of winter, a major storm is hitting Colorado and heading for the Plain states. Denver's airport now closed because of wind and heavy snow. So are some major interstate highways, so let's get the latest from meteorologist Reynolds Wolf. He's at the CNN Center in Atlanta. Hey, Reynolds. (WEATHER REPORT)

COSTELLO: All right, thanks, Reynolds. Bad weather on Oregon's Mt. Hood has forced crews to suspend the search for those two missing climbers. Officials actually have given up hope of finding the men alive. Brian Hall and Jerry Cooke haven't been seen now for 12 days. A third climber's body was recovered on Monday.

More news at the bottom of the hour. CNN PRESENTS: After Jesus starts right now.

LIAM NEESON, ACTOR: It's a dangerous, tumultuous time in the Roman Empire. Nowhere more so than in the province of Judea, on the far edge of the Mediterranean.

Its capital, the holy city of Jerusalem, is teeming with pilgrims for the springtime feast of Passover, many of them looking for an earthly king, a messiah who will deliver them from the yoke of Roman oppression.

Into this powder keg walks Jesus of Nazareth. His protests against the Romans make him a popular hero. To some, he is the messiah. But to the Romans, he is political trouble. So they crucify him.

The followers of Jesus believe that he has risen from the dead and will soon usher in the kingdom of heaven. But when and how will this new faith survive after Jesus?

Today, more than two billion people call themselves Christians, people who believe Jesus rose from the dead. But perhaps it's a real miracle that Christianity did not disappear when the Romans crucified Jesus on a lonely hill outside Jerusalem almost 2,000 years ago.

PROF. CLAIRE PFANN, UNIV. OF THE HOLY LAND, JERUSALEM: This region, Jerusalem and Judea, represented an important land bridge between Syria and Egypt. So throughout history, this has been a critical place. NEESON: Jerusalem had been the holy city of Judaism for more than 1,000 years, a place that the Romans had occupied since 63 B.C. At the time the Romans killed Jesus, around 30 A.D., scholars say, the Jews were desperate for a messiah to free them from Roman oppression, to liberate them and their promised land.

But even then there was disagreement as to who that messiah might be.

PROF. AMY-JILL LEVINE, VANDERBILT UNIV. DIVINITY SCHOOL: In the first century, there was no messianic checklist. Some people would have followed Jesus and considered him to be the messiah, God's anointed one. Others followed John the Baptist. Others followed additional figures.

NEESON: In the cosmopolitan city of Jerusalem, with its massive temple, the holiest site on earth for Jews and its regal priestly caste, would many have even noticed Jesus, the wandering rabbi from the Galilee?

PROF. BART EHRMAN, UNIV. OF NORTH CAROLINA, CHAPEL HILL: It's a good question whether Jews in Jerusalem at the time would have even known about the sect of Jewish Christians, people who believed that Jesus was the messiah.

PROF. JUDITH LIEU, KING'S COLLEGE, LONDON: He would have looked the same as everybody else. He dressed the same as everybody else. He had perhaps some disciples, some people following behind him.

When you think of the temple, it's a place where there's a lot of activity, a lot of coming and going, no pews, then he would not necessarily have stood out to everybody.

NEESON: And his execution might have been equally obscure.

PFANN: The Romans executed hundreds of thousands of people in the Holy Land in the first century B.C. and A.D. and another person being crucified it's almost part of everyday activity.

NEESON: In fact, the Jesus story looked to be over even before he died. After all, Jesus had been betrayed by his own disciple, Judas. And as Jesus had foretold in the gospels, his chief disciple, Peter, had already publicly denied him three times.

Only a few women, led by his mother, Mary, stayed at the foot of the cross.

PFANN: Outside of the women who remained there watching, the picture we get from the gospels is that most of his followers actually ran away and hid, because they were afraid for their own safety.

NEESON: That should have been the end of the Jesus story and it might have been, if not, the gospels tell us, for the women, namely, Mary Magdalene and Mary, mother of Jesus.

Three days after his death, they discovered his empty tomb. As he promised, Jesus had risen from the dead.

REV. ROBIN GRIFFITH-JONES, MASTER OF THE TEMPLE CHURCH, LONDON: This is the key moment. What happened in the days after Easter and how did the news spread?

NEESON: The new faith had another revelation. The resurrected Jesus appeared to his disciples. According to the Acts of the Apostles, Jesus told them to stay in Jerusalem, where they would soon get a sign from heaven, baptized with the Holy Spirit.

PFANN: So they sit there in a state of anticipation and expectation, but not really knowing.

NEESON: Then on the Jewish feast of Pentecost, 50 days after Jesus died, the sign came and, suddenly, from heaven, there came a sound like the rush of a violent wind. And it filled the entire house where they were sitting, divided tongues, as of fire appeared among them, and a tongue rested on each of them. All of them were filled with the Holy Spirit and began to speak in other languages.

LEVINE: So that Jews who were in Jerusalem, be they from Egypt or Syrene or Greece or even Rome, would be able to understand this new proclamation in their own dialect.

EHRMAN: And so now, all of a sudden, 8,000 Jews in Jerusalem have converted and before long, there won't be any non-Christian Jews left, according to the Book of Acts.

NEESON: The story in the Book of Acts was written by Luke decades later. Could he have exaggerated to make it sound even more impressive?

GRIFFITH-JONES: I think it most unlikely that it happened exactly as Luke describes it, but Luke is absolutely clear what significance he sees in what happened, and what he needs to do is relay through his story not just what happened, but what it meant that it happened, what it signified.

And so he draws on the Old Testament and we have this wonderful image of all the nations of the earth being reunited under this renewed blessing and law of God.

NEESON: Less than two months after the violent death of Jesus, his once terrified followers were now boldly proclaiming his divine rule. It would seem that Christianity had already taken root, though its followers didn't see it that way.

EHRMAN: These earliest followers of Jesus understood themselves to be Jews. They thought that Jesus was the Jewish messiah who had been sent from the Jewish god to the Jewish people in fulfillment of the Jewish scriptures.

LEVINE: So they're not, at least originally, interested in starting a new religion. They're interested in preparing the world for its final consummation. NEESON: But that kingdom doesn't come and it claims the followers of Jesus start to make about him begin to sound like blasphemy.

PROF. LAWRENCE H. SCHIFFMAN, NEW YORK UNIVERSITY: So the problem is not in the belief that Jesus is the messiah. The problem is when the belief is moving from messiah to a kind of deified messiah and as this begins to be understood by the Jews, then opposition to this movement is no longer a political thing. It's a very strong religious thing.

NEESON: In fact, it will come to bitterly divide the family and lead to centuries of persecution. But now, in the years after the death of Jesus, his followers needed to keep his message alive.

And they get two messengers who could not be more different, Peter, the simple fisherman from Galilee, who was Jesus' chief apostle, and Paul, a sophisticated Pharisee. Together, they will create a religion that would change the world.

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NEESON: Just a few years after Jesus was killed, the Book of Acts tells us, a devout Jew named Stephen stood on the steps of the temple in Jerusalem, the holiest spot in all of Judaism, and directly challenged the religious establishment.

He proclaimed the Jews had rejected the messiah and so the temple would be destroyed. The only way to salvation was through Jesus, the son of God. It was blasphemy.

EHRMAN: And according to the traditions in the Book of Acts, as he's being stoned to death, he looked up to heaven and he saw Jesus himself standing by the right hand of God. And he prays to Jesus that he not hold this against his persecutors, and then he dies.

NEESON: The martyrdom of Stephen was a gift from heaven and a propaganda coup. Just like Jesus, his followers were willing to prove their faith with their lives.

But for one young man who participated in the stoning of Stephen, getting rid of blasphemers was the mission. His name was Saul. Born in Tarsus, in Asia Minor, he was a Pharisee, a member of a powerful Jewish movement.

EHRMAN: And he thought that this was a blasphemous idea, that the messiah would be somebody who was crucified, because for most Jews, the messiah must be a figure of grandeur and power. How can you say that a crucified man is the messiah?

PFANN: As he understands it, the appropriate response to this is to persecute, to cut out, to destroy this messianic Jewish movement that is happening, that is focused on Jesus of Nazareth, and that's what he does.

NEESON: Saul was at the forefront of that persecution, says the Book of Acts. Breathing threats and murder, Saul set off in furious pursuit of Jesus' followers, who had fled to Damascus.

GRIFFITH-JONES: Damascus was a holy place and there were those who thought the messiah, the Christ, would appear in Damascus.

NEESON: But while on the road to Damascus, Saul had an extraordinary vision. Suddenly a light from heaven flashed around him, says the Book of Acts. He fell to the ground and heard a voice saying to him, "Saul, Saul, why do you persecute me?" He asked, "Who are you, Lord?" The reply came, "I am Jesus, whom you are persecuting."

PFANN: And when he finds out that Jesus is truly alive, it means that the other things that Jesus' followers say about him must also be considered as true. Jesus is the messiah.

NEESON: Saul of Tarsus, who never met Jesus in the flesh, never traveled or supped with him, and who wanted to kill his followers, becomes the greatest defender of the Jesus faith, known to the world by the Greek version of his name, Paul.

EHRMAN: Some people have called Paul the second founder of Christianity, because Christianity is more than following the teachings of Jesus. Christianity is not just a religion that Jesus had. It's the religion about Jesus. It's a religion founded on Jesus' death and resurrection.

NEESON: In his letter to the Galatians, Paul reveals exactly what Jesus told him to do, that "I should announce him triumphant among the Gentiles." It was a radical mission.

PROF. RICHARD A. FREUND, UNIV. OF HARTFORD: He starts preaching there to Gentiles, to pagans, and saying, "This is a faith that can touch you," and that must have been -- the Jews in the Diaspora must have said, "My gosh, did we miss something? When did they suddenly make Judaism into a universal religion?"

NEESON: People listened to Paul because he was the perfect man for the job, able to speak to both Jews and Gentiles in their own language.

EHRMAN: So he's one of the first really powerful intellects to convert to Christianity in the first century.

NEESON: Just what did this cosmopolitan Jew say to the pagans to make them give up their ancient gods and believe in Jesus?

EHRMAN: This is the one who could heal your child, if your child was sick. This is the one who could end the draught, who could end the famine. This is the god who could raise the dead, that this was the god who could do miracles, and so this was the only god to be worshiped.

NEESON: Indeed, Paul's first mission abroad was so successful that, for the first time, the followers of Jesus get the name by which they will be known forever.

PFANN: And after the apostles, Luke tells us that it was an Antioch that the believers were first called Christians.

EHRMAN: There's some evidence to suggest that the term "Christian" itself was actually used by the opponents of the followers of Jesus as a term of derogation, that, in fact, these are Christians, these are little Christs. And who was Christ? He was the one who was crucified. That's what these people deserve, as well.

NEESON: The Christians now had a name and an identity of their own. It marked the beginning of the public split with Judaism.

LIEU: Both claim the same heritage going back to Abraham. At some stage, you begin to give yourself a label, or perhaps other people begin to give you a label, and labels themselves begin to set up differences. They begin to make you aware of differences.

NEESON: But delivering the Jesus message put Paul and Peter in conflict. Paul's open door mission to the pagan Gentiles was a huge problem for Peter, who thought the resurrection of Jesus was for the Jews alone. If you wanted to follow Jesus, you had to become a Jew and obey Jewish law. And Peter wielded considerable power back in Jerusalem, power given to him by Jesus.

LEVINE: According to the gospel of Matthew, Jesus says to Peter, "You are Peter -- the Greek term for rock, petros -- and on this rock, petra, I will build my church."

EHRMAN: Peter became the head of the small Christian church that was centered in Jerusalem itself. So early on, Peter was the key player in early Christianity and, according to our tradition, was the one that converted Jews early on to believe in Jesus and the messiah.

NEESON: But there was another crucial leader of the early followers of Jesus. His name was James and he seemed to have the ultimate trump card in the new faith.

EHRMAN: Because he was Jesus' earthly brother, he was actually raised in prominence among the Christians of Jerusalem and eventually, then, it wasn't long before he became the leader of the Jerusalem church.

NEESON: And James agreed with Peter: Jesus was for the Jews.

Within two decades of the crucifixion of Jesus, scholars say, Christianity faced a life or death moment.

EHRMAN: This was the major dispute in early Christianity, whether followers of Jesus have to become Jewish in order to worship the Jewish god.

NEESON: The conflict threatened to destroy the new faith. How could it be saved?

PFANN: In Jerusalem, around the year 48 to 49, the first apostolic council is called in order to resolve the issue of Gentile Christians, do they convert or don't they convert. LEVINE: Paul argues that the Holy Spirit had descended upon the Gentiles apart from the Law of Moses. Therefore, there was no reason to insist that those Gentiles be converted first to Judaism in order to be a member of the church, and James, the brother of Jesus, presiding over this Jerusalem council, agrees with Paul.

NEESON: It was a huge triumph for the new faith and especially for Paul, whose argument had won the day. The Jesus message was for the whole world, and those who believed that message would win eternal life.

But the biggest test was yet to come. Just how will the Jesus message go down in the pagan heart of the Roman Empire?

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NEESON: In the first century A.D., the Roman Empire was home to more than 60 million people and dozens of religions.

At the center of it all, Rome, a city of a million people. To spread the word of Jesus, the missionaries now had to conquer that empire, and first into Rome was the simple Galilean fisherman, Peter.

LEVINE: Would Peter have been in awe? Of course, he would have been, but Peter had a message which he was convinced would put in awe all those people of Rome.

NEESON: Believers in Jesus also provided answers to the central mystery of life.

LEVINE: The questions pagans were asking were, "What was going to happen to me when I died? How do I get forgiveness from sin?" The Christian church said, "We can provide you those answers."

NEESON: Believe in the resurrected Jesus and win eternal life. That was the message that had appeal across the Roman Empire, a message that first spread throughout the huge Jewish community outside Israel.

LEVINE: Over a million Jews in Egypt and Alexandria, Jews in Damascus, Jews in Antioch, Jews in Athens, certainly Jews in Rome -- and for the early Christians, these early followers of Jesus, some of these Jews would have provided missionaries a home, missionaries a base by which they could reach other Jews, as well as Gentiles.

EHRMAN: The Romans had provided roads throughout the entire empire. They had gotten rid of many of the pirates that were on the seas. There was a common currency throughout the empire. Travel was both possible and feasible and so it wasn't unusual for somebody like Paul to be able to travel around to different places.

GRIFFITH-JONES: And Paul never stopped. He just never stopped, on either by foot across the great land mass of Asia Minor or by sea, particularly, across the Aegean, to and fro from east to west. LEVINE: But we cannot discount the force of Paul's own personality. Religiously speaking, Paul was a genius.

NEESON: Paul not only set up Christian communities, he also directed them from afar, writing letters, or epistles, to keep them on the Jesus message. Paul's epistles to these various Christian communities are the earliest surviving Christian documents, older than the gospels.

And he preached everywhere, from small town synagogues to Athens, the center of world culture, convincing philosophers and slaves alike that God had sent his son, Jesus, to die and rise again to save everyone.

In his letter to the Romans, written in 57 A.D., Paul says that, "By God's will, I may somehow at last succeed in coming to you."

Nearly three decades after the death of Jesus, Paul would make his way to Rome, but only after he was jailed in Jerusalem, where he found himself threatened with death.

LEVINE: I can picture him just trying to convert the entire Praetorian guard. The early Christians, particularly the evangelists, the apostles, were politically problematic. They were proclaiming a son of God, a god from God, a savior, but those happened to be titles that the Roman emperor arrogated to himself.

NEESON: For the next few years, Paul would languish in prison, surviving assassination attempts and brutal interrogations.

Finally, his appeals to be tried in Rome were answered.

PFANN: Paul is a citizen of the Roman Empire and that provides certain protections for him. They include the right to a trial, the right to not be whipped or beaten without a trial, the right to appeal to Caesar, and a protection against crucifixion.

NEESON: The trip from Jerusalem almost killed Paul, when he was shipwrecked in a storm. Finally, in the year 60 AD, Paul reached Rome, in chains, just in time for Rome's first official persecution of Christians, at the hands of the emperor, Nero.

In the year 64 AD, when a fire destroyed much of imperial Rome, Nero famously fiddled while the city burned. But he had his reasons for letting the fire burn. He wanted to clear out space for grand new buildings.

GRIFFITH-JONES: The Christians, living in the south of the city, are immune from the fire that weeps northwards. The Christians fall under suspicion. Nero, the emperor, being blamed widely, realizes the Christians are the scapegoats, the natural scapegoats.

EHRMAN: He apparently had some of them burned as human torches in his gardens. He had others wrapped in animal skins and set wild dogs upon them in a public setting. And so this was the first persecution of Christians by a Roman emperor. The reasons Christians were persecuted early on was not because it was illegal to be a Christian. They were persecuted because they were known to be troublemakers.

NEESON: Among Nero's victims were the two most important leaders of the early Christian church. Peter had been living and preaching in Rome. Paul had been living under house arrest.

Now, they were both condemned to death for their faith.

PFANN: Peter is not a citizen of the Roman Empire and so he is able to be crucified. And he is crucified upside down, because he did not feel that he was worthy to die in the same manner that Jesus did.

NEESON: And Paul, who spread Christianity throughout the empire, was beheaded.

Two years earlier, James, the brother of Jesus, had been stoned to death in Jerusalem. Now, Peter was gone and Paul, too. The head, the heart of the faith.

If Jesus hadn't saved these three, what then for Christianity?

EHRMAN: Once these people died, there were already leaders in place who could take over the mantle of leadership and then lead Christianity on into the future.

NEESON: Christians weren't the only ones facing violent martyrdom. Back in Judea, in the birthplace of Christianity, Judaism was about to undergo the most horrific trial in its tortured history.

Rebellion, then war with Rome. The terrible outcome would crack open the growing rift between the Jews and the Christians for the next 2,000 years.

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COSTELLO: Hello, I'm Carol Costello in New York. CNN PRESENTS: After Jesus will continue in just a moment. But first, a quick check of the day's top stories.

The search for two missing climbers on Oregon's Mt. Hood has been suspended again because of bad weather. But officials have given up hope of finding either Brian Hall or Jerry Cooke alive. An autopsy release late today indicates a third climber in the party, Kelly James, had been dead for several days before his body was found last Sunday. James died of hypothermia.

A major winter storm hit Denver, Colorado, during this morning's rush hour. Highways slowed to a crawl, then closed down completely. Denver's airport has closed and hundreds of flights have been canceled, stranding even more travelers. Up to two feet of snow expected to pile up in Denver before the storm moves into the Plains. Blizzard warnings are up for eastern Colorado and adjoining sections on Nebraska and Kansas. And literally thousands of one-armed bandits are coming to the city of brotherly love. Pennsylvania officials today approved five licenses for stand-alone slot machine parlors. Two of them will be in Philadelphia. Now that means it will become the nation's biggest city with casinos. The state's gaming board rejected Donald Trump's bid for a slots parlor. It also turned down plans to build them near the historic Gettysburg battlefield and next to Pittsburgh's Mellon Arena.

Quick break, we'll have more news at the top of the hour, and then it's back to CNN PRESENTS: After Jesus.

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NEESON: In the year 66 AD, the Jews of Israel had seen enough of their Roman masters and launched a revolt that would end in disaster and permanently divide them from their Christian brothers.

EHRMAN: There was a serious uprising in which Jews decided to try and throw out the Roman oppressors and establish Israel as a sovereign state in the land.

NEESON: The Romans sent in their legions from Assyria and fought their way south through Galilee to Jerusalem, the holy city of Judaism and fortress of the Jewish rebels.

SCHIFFMAN: They made the tactical mistake of all assembling in Jerusalem around that temple. Then the worst thing happened. They started to fight among themselves about what to do, how to defend themselves.

NEESON: That's when, according to the Jewish historian Josephus, the Roman general, Titus, surrounded Jerusalem. Titus, a brutal warrior, cut off the city's food and water in an attempt to starve the people out.

LEVINE: Meanwhile, he waited for Jewish faction A to defeat Jewish faction B. He let the internal revolutionaries fight the battle for him.

NEESON: Titus and his troops then breached the walls of Jerusalem. They attacked the temple, slaughtering more than half a million Jews with sword, fire and crucifixion.

EHRMAN: The Temple Mount was a huge area. You could fit 40 American football fields inside the Temple Mount, within the walls. Much of it was plated with gold and with fine wood and so, from a distance, it would sparkle.

FREUND: Every single Jew had an obligation to make three pilgrimages a year to the temple in Jerusalem and people who lived in Judea felt that obligation very seriously. The idea of pilgrimage was central to a Jew's identity.

NEESON: The temple's majesty and its importance to the Jews made it the perfect target for the Romans to make clear exactly who was king of the Jews -- Rome. So the Romans burned the temple to the ground and Titus and his men seized the spoils of war.

PFANN: The gold was melted down, the silver was melted down and these precious metals were actually used in facing of the coliseum, to adorn the coliseum.

As all conquerors do, they took the wealth for themselves.

NEESON: The destruction of the temple was devastating and symbolic, further dividing Jews and Christians.

Jesus had prophesied the end of the temple. "Truly, I tell you," he said to his disciples, "not one stone will be left here upon another. All will be thrown down."

LEVINE: For the Christians, the destruction of the temple was punishment on the Jews for their rejection of Jesus.

NEESON: Some Jewish rebels managed to escape and made their way to a hilltop fortress called Masada. But that, too, ended in tragedy when the Romans built a ramp to penetrate the fortress.

EHRMAN: When this happened, the Jewish insurgency within the walls then took a suicide pact. They killed one another until the last ones then killed themselves.

And so when the Romans finally arrived at the fortress, in fact, all they found were dead bodies.

NEESON: Now, with their rebellion crushed, with hundreds of thousands dead and with their temple gone, the Jews were in danger of disappearing altogether.

FREUND: There was no central temple. There was no leadership. Remember, this had been in place for a 1,000 years. They have had this same structure for a 1,000 years. Now, it was over.

Many other religions had folded up their tents, you know, with far less.

NEESON: But it wasn't quite over. Rabbi Yochanan ben Zakkai had escaped the besieged Jerusalem, smuggled out in a coffin.

He made an appeal to the newly appointed emperor, Vespasian, asking to set up a peaceful rabbinical academy in the nearby town of Yavneh, promising that it would be purely religious and not political or military in nature.

Surprisingly, Vespasian agreed and only a year later, in 70 A.D., the rabbi's academy represented Judaism's last hope.

FREUND: And he brought these scholars together in Yavneh and he built, for the first time, what would become the basis for a new type of Judaism that would then run parallel with the beginnings of Christianity. NEESON: From the ruins of the temple, two separate and distinct faiths emerged.

EHRMAN: Some people have thought that this destruction of Jerusalem in the year 70 led to a major break between Judaism and Christianity, in part, because there were many Jews who didn't want to side with the Jewish rebels in fighting against the Romans, because for these followers of Jesus, salvation doesn't come by overthrowing the Romans. Salvation comes by believing in Jesus.

NEESON: At the end of the first century, Christian leaders decided they needed a new holy scripture. They started writing down what Jesus had said and done. And now Christianity would take a new direction, a religion based on the word of the written gospels, a religion that would guide them far into an uncertain future.

But just who wrote the gospels and are they, indeed, the last word on Jesus?

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NEESON: By the end of the first century, Christianity was adrift. The followers of Jesus, persecuted by the imperial powers in Rome, estranged from the Jewish religion from which they had come.

Their founding leaders were dead and the great temple of Jerusalem was gone. Israel lay in ruins.

Jesus promised he would return to save his loyal followers, but he had not. If ever there was a time of peril for Christianity, this was it.

PFANN: The delay in the Second Coming caught everybody by surprise. I don't think any of the earliest Christians thought they would be around for a 100 years or 200 years or even 300 years.

GRIFFITH-JONES: Jesus' delay was, indeed, a crisis, which is why the New Testament has so many times to address the question, "Oh, where is he? Why hasn't he come back? When's he coming?"

Why didn't it just break John into a sort of collapse of disappointment and disillusion?

NEESON: It didn't break down, because Christian leaders decided they needed something more permanent to preserve the faith in Jesus. So they compiled a history, sacred books and a clergy to stand in for Jesus. But that didn't happen overnight.

EHRMAN: I think most people imagine that after Jesus died, the Church just emerged suddenly and that you had Christians confessing the Nicean Creed, reading the canon of the 27 books of the New Testament, and that it was all in place right after Jesus' death. And, in fact, it took centuries for these things to fall into place.

NEESON: The core of Christian belief is the story of Jesus' life, death, and resurrection, as told in the four gospels, the books of Matthew, Mark, Luke and John, named after the evangelists said to have written them.

EHRMAN: Matthew and John were two of the disciples of Jesus, Matthew the tax collector and John the beloved disciple. Mark was a companion of the apostle Peter and Luke was a companion of the apostle Paul.

NEESON: But did they really write the gospels?

GRIFFITH-JONES: We can never be sure. What could happen, it's easy to imagine, that in days such as that, Peter was relaying to some young pupil the stories he remembered, before it was too late, and Mark is putting them into an order in which this story will offer some consolation to a church that is facing terrible destruction.

NEESON: Mark is the earliest gospel, scholars say, written around 65 AD. Matthew and Luke were written some 15 to 20 years later. And, finally, the gospel of John was written about 90 or 95 AD.

While each of the four gospels recount the death and resurrection of Jesus, they are strikingly different.

EHRMAN: The question of where they got their information is very interesting. What most scholars today think is that after the days of Jesus, his followers told stories about him, about what he did during his ministry.

And these stories were circulating year after year, decade after decade, until later authors, who were not the illiterate Aramaic followers of Jesus in Galilee and then Jerusalem, but were Greek- speaking Christians of a later generation, these later authors heard these stories and then wrote them down in their books.

NEESON: The gospels were written not as history, scholars say, but as a kind of divine story, a gospel truth.

GRIFFITH-JONES: When we now read these gospels as straightforward narratives, we completely miss their point. We are trying to make them into a diary. They're not a diary. We're trying to make them into a biography. They're not a biography.

They are what, in our terms, should be called an apocalypse, a disclosure of a truth, which -- a supposed truth, which the gospel writers themselves believed was beyond all normal human apprehension.

NEESON: And they were aimed directly at the Jews who had not embraced Jesus as the messiah. So by the end of the first century, disagreement had become a deepening divide, further driving Christians from the Jewish faith.

GRIFFITH-JONES: By the time we get to John, we hear talk of those who respected Jesus being thrown out of the synagogue, yes, and how the enemies in John's gospel are the Jews. It's left a terrible legacy in Christendom.

LIEU: If you read your gospel carefully, then sometimes you have to stop, and you're rather perplexed by this, because Jesus is a Jew, his disciples are Jews. Actually, all the characters are Jews.

So when the Jews challenge Jesus and his disciples, you should say, "Hang on a minute, they're all Jews. What do we mean by this?"

FREUND: They're Jewish and they're writing about other Jews. And it's like I can call my mother names, but you should not call my mother names. This was an inter-brotherly, sisterly fight for a definition of Judaism. And, yes, they did not like what other Jews were saying, but they were also themselves Jews.

NEESON: Scholars say that the final split came early in the second century, when the Jews of Israel launched another rebellion against Roman rule, led by their messiah, Simon Bar Kokhba.

SCHIFFMAN: The Jews in the rebellion thought that Bar Kokhba was their messiah, which meant that they had already rejected the Christian notion of messiah.

NEESON: The Bar Kokhba rebellion ended with the slaughter of hundreds of thousands of Jews, including their messiah.

But Christianity soon had a new fight and the enemy came from within. As Christianity's second century began, its leaders now battled heretics, the monks and mystics who wrote their own Jesus stories, gospels that would threaten this young religion.

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COSTELLO: Hello. I'm Carol Costello in New York.

CNN Presents: "After Jesus" will continue in just a moment, but, first, a quick check of the day's top stories.

Just in time for the official start of winter, a major storm is roaring out of the Rocky Mountains and into the Plain states. Denver, Colorado's airport now closed -- hundreds of flights have been canceled. Heavy snow also is snarling travel in New Mexico, Kansas and Nebraska. Portions of Interstate 40, 70, 80 are shut down.

Bad weather on Oregon's Mount Hood has forced crews to suspend the search for two missing climbers. Officials have now given up hope of finding Brian Hall and Jerry Cooke alive. An autopsy released today shows a third climber, Kelly James, died of hypothermia.

In what will likely be his last White House news conference of the year, President Bush acknowledged today that things are not going well in Iraq. He said he still hasn't decided whether to order a sharp increase in the number of U.S. troops there, but he does want to increase the overall size of the U.S. military.

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GEORGE W. BUSH, PRESIDENT OF THE UNITED STATES: I'm inclined to believe that we need to increase in -- the permanent size of both the United States Army and the United States Marines. I have asked Secretary Gates to determine how such an increase could take place and report back to me as quickly as possible.

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COSTELLO: Defense Secretary Robert Gates was in Baghdad today to confer with U.S. commanders, just two days after taking charge at the Pentagon. The Associated Press is reporting, the Pentagon is pushing President Bush to request nearly 100 billion more dollars for the wars in Iraq and Afghanistan.

Now back to CNN PRESENTS: "After Jesus."

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NEESON (voice-over): By the start of the second century, Christianity was at a crossroads.

After the crucifixion of Jesus, around 30 A.D., the New Testament recounts how the faith he started took on a new life. Inspired by the leadership of the apostles Peter and Paul, the message of the resurrected Jesus spread into the heart of the Roman empire.

But success brought persecution and death. As Christianity's early leaders began to die out, it was critical to keep the story of Jesus alive. So, they compiled sacred books about his life, what we know today as the New Testament.

But to the south, in the desert sands of Egypt, a group of Christian monks and mystics were writing their own gospels with a very different version of the life of Jesus, one that launched a battle for the very heart of Christianity.

Of all the threats to Christianity over the past 2,000 years, perhaps the greatest came in 1945, near the village of Nag Hammadi in southern Egypt, where the waters of the Nile dry up into desert sands.

This is where a farmer named Muhammad Ali was digging for fertilizer when he discovered a clay jar with 13 ancient books hidden inside.

MARVIN MEYER, PROFESSOR, CHAPMAN UNIVERSITY: Within these books, there were over 50 texts, most of which we did not know about before, that could help us understand the beginnings of Christianity and the development of religion in some remarkable new ways.

NEESON: But it all nearly vanished in a puff of smoke, when the mother of Muhammad Ali was looking for fuel to make some tea.

MEYER: She found these old books. And, as he told the story, Muhammad Ali says that his mother ripped out some pages of papyrus, some precious pages of ancient text, and pushed those underneath her stove, and burned the papyrus, and had some delicious tea that day. But what was lost in the process, we will never know.

NEESON: What we do know is that the surviving books, called the Gnostic Gospels, gave the world a compelling and competing story of what happened after Jesus. MEYER: The texts of the Nag Hammadi library are making it very clear that there were a lot of gospels that were composed in the early church. Four were finally selected for the New Testament canon, but, beyond that, there were plenty of other gospels.

NEESON: Other gospels, more than one version of the faith? In fact, there were many. There were even Christians who believed in more than one god.

BART EHRMAN, PROFESSOR, UNIVERSITY OF NORTH CAROLINA, CHAPEL HILL: All of these groups said that they were following the teachings of Jesus, and that they themselves were the true Christians, and that the other groups are wrong.

NEESON: By far, the most successful and threatening was a group called the Gnostics, who lived in Egypt in the second century. And they wrote their own version of the life of Jesus.

MEYER: The word "Gnostic" comes from the Greek "gnosis," which means knowledge, but it's not the kind of knowledge that you simply get out of books, but, rather, it is mystical knowledge. It is insight into the true nature of -- of who you are, and what is your relationship to God, and is there an essence, a spark, a bit of the light of God within your own self.

NEESON: But finding God within yourself was blasphemous, according to Orthodox Christians. They believed that God had created everything, and his creation was perfect, though man had sinned in the Garden of Eden. The Gnostics saw it differently.

EHRMAN: According to Gnostics, this world we live in, this material place is not the creation of the one true God. This is a cosmic disaster that happened, and there are people who are trapped here in human bodies.

REVEREND ROBIN GRIFFITH-JONES, MASTER OF THE TEMPLE CHURCH, LONDON: But there is hope, because some of us, just some of us, will be woken up by the redeemer coming to us from the world of the spiritual, and will reintroduce us to our real destiny, which is to rise again from this material filth, through layer after layer of the heavens, to the true spiritual realm.

It's very attractive. It offers a form of -- of self-discovery, of self-truth, self-realization.

NEESON: The Gnostic message was very seductive: a mix of Greek philosophy, Egyptian religion, and Eastern mysticism, all very contemporary in its spirituality.

MEYER: The New Testament Gospels are gospels of the cross. The Gnostic gospels are gospels of wisdom. The New Testament Gospels care about salvation from sin. The Gnostic gospels care about salvation from ignorance. The New Testament Gospels look to stimulate faith. The Gnostic gospels look to stimulate knowledge and insight.

NEESON: Gnosticism held a fascination for many Christians for another reason. Its gospels seemed to offer a more female-friendly faith.

MEYER: It was the Gnostics that thought that the role of the female as an image and the role of women within the church should be advanced, so that God is not only male; God is also female. There are not only male leaders; there are female leaders. There are not only male priests; there are female priests. And, in this way, there is a kind of gender balance found in these texts.

NEESON: That balance is not found in the Gnostic gospel of Thomas, where Peter asks Jesus to send Mary Magdalene on her way, for women aren't worthy of apostolic life.

EHRMAN: And Jesus replies, "Leave her alone, for I shall make her a male, for every woman who becomes a male will enter into the kingdom of God."

This isn't a very liberating view of women, and not one I think that people probably want to latch on to today.

NEESON: The Gnostic gospels seemed to assault the very foundation of Orthodox Christianity, telling a different version of the life of Jesus.

Not only does doubting Thomas have a gospel, but so does Judas Iscariot, the apostle who betrayed Jesus for 30 pieces of silver.

MEYER: The gospel of Judas Iscariot? What a provocative thought that is, that there could be good news or a gospel that is associated with the person who is most renowned as the betrayer of Jesus. And, now, lo and behold, a gospel of Judas has been discovered, shedding more light on how provocative and interesting and insightful that second century was, with all the diversity of thoughts, so that even a figure like Judas can be linked to the good news of Jesus.

NEESON: So, too, can Mary Magdalene. For centuries, mistakenly depicted as a repentant prostitute, she is the chief apostle in her own Gnostic gospel, and much more than that to Jesus in the Gnostic gospel of Philip.

MEYER: In the gospel of Philip, it is said that Jesus loved Mary Magdalene more than all the other disciples and he used to kiss her often on her -- and then there is a lacuna, or a hole, in the text. You would think, probably, it means on her lips, as a matter of fact.

But it says something about the perception in that particular text of the closeness of Jesus and Mary Magdalene. Mary was a beloved disciple of Jesus.

NEESON: But scholars tend to read that passage as symbolic, rather than as a literal relationship, or secret marriage, between Jesus and Mary Magdalene.

EHRMAN: Scholars have not been persuaded over the years that Jesus was married. We know of Jews from the first century, in fact, who were unmarried. And it's striking that the Jewish men that we know of who were single and celibate were men who have shared the same point of view as Jesus.

NEESON: Perhaps the biggest problem with the Gnostic gospels is that they were written decades, and even centuries, after the Gospels of Matthew, Mark, Luke and John. For some historians, that passage of time raises serious questions of authenticity.

LAWRENCE H. SCHIFFMAN, PROFESSOR, NEW YORK UNIVERSITY: The Gnostic gospels are not early sources of Christianity. They're documents that came into existence way after the actual Gospels had come into existence.

They also don't fairly represent Christianity as what it was, namely, a group that had its origins in Judaism. In fact, some of these documents are essentially anti-Semitic. And that's why they want to deny the Old Testament origins of Christianity, let alone to deny the real human role of Jesus in Judea in the first century.

NEESON: Gnosticism, to church leaders, was heresy. And, to survive in this dangerous time, the church had to be united. Over the next two centuries, the sacred Gnostic texts would be suppressed, hidden or destroyed, while Orthodox Christianity constructed great temples and claimed authority over the Bible.

Even so, Christianity would face its greatest challenge: methodical, brutal persecution by the Roman Empire.

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NEESON (voice-over): The landscape of Christianity today looks very different than it did in the first century. Back then, there were no steeples, no pews, no altars, no churches, as we know them. Even the Christmas holiday did not exist.

RICHARD A. FREUND, PROFESSOR, UNIVERSITY OF HARTFORD: The simplest things, like the date when Jesus was born, was totally fluid through the second and into the third century. It only appears for the first time on a Christian calendar in the fourth century as December 25.

So, you get the feeling that the entire coalescing of the religion of Christianity is taking place over 100, 200 years after Jesus is no longer walking the face of the earth.

NEESON: The structure familiar to contemporary Christians began in the first years of the faith with a simple act, as Christians would hold their primary worship on a Sunday, the day Jesus rose from the dead, and not the Saturday Sabbath of the Jews.

EHRMAN: Paul speaks of Christians gathering together on the first day of the week. And they apparently sing hymns. They apparently read scripture. They take a collection of alms for the poor, and they celebrate what came to be known as the Eucharist. PRIEST: This is my body, which will be given up for you.

NEESON: Eucharist, from a Greek word meaning thanksgiving, was the early Christian celebration, a recreation of the Last Supper.

CLAIRE PFANN, PROFESSOR, UNIVERSITY OF THE HOLY LAND, JERUSALEM: The one ritual that Jesus established for his communities was to share bread and wine in remembrance of him.

UNIDENTIFIED MALE: Do this in memory of me.

PFANN: And throughout all the Christian communities, whether they were Jewish Christians or Gentile Christians, that partaking of the bread and the wine in his memory became the central focus of worship.

NEESON: But that Eucharist would have looked much different than the ritual we see today, as Paul reveals in Corinthians.

JUDITH LIEU, PROFESSOR, KINGS COLLEGE, LONDON: But the Lord's supper, as he describes it, it is not a sort of different sort of practice with those tiny, wee little wafers or bits of bread and a thimble full, or, you know, a sip of wine or something. It's something which is integrated into a normal meal. He talks about some people going away hungry and other people having too much. So, it's -- it's integrated in a normal social sort of context.

NEESON: And while the New Testament mention the idea of a church, using the Greek word "ecclesia," early Christians did didn't worship in magnificence cathedrals.

AMY-JILL LEVINE, PROFESSOR, VANDERBILT UNIVERSITY DIVINITY SCHOOL: Ecclesia simply means an assembly. Early Christians, early followers of Jesus would have met in private homes. They might have met in public buildings.

PFANN: They began in the synagogue. They broke from the synagogue. And they met in houses.

In Corinth, where you have very wealthy Gentile Christians and Jewish Christian leaders, you would have a villa. And maybe a villa could host 75 or 100 people at one time.

REVEREND GERALD O'COLLINS, S.J., PONTIFICAL GREGORIAN UNIVERSITY, ROME: So, baptism took place at home, and also the Eucharist. The Eucharist has its roots in the Last Supper.

NEESON: But who presided over these rituals was then an open question.

EHRMAN: The earliest Christian churches were not organized according to a hierarchical structure, such as we think of today, where there might be a pope, for example, in the Catholic Church, or there be bishops over churches, or priests, or -- or even pastors over churches.

The early Christian communities, in fact, were completely egalitarian.

NEESON: But a hierarchy did begin to emerge, taking on the form of the society around this young church, and building on the vocabulary of the New Testament itself.

PFANN: Words like "episkopos," which means a pastor, but comes -- or a shepherd -- but comes to mean a bishop, words like "presbyteros," which means an elder, but comes to mean an overseer, or words like "diakonos," which means a servant, but comes to mean deacon, all of these things are inherent already in the New Testament.

We see, though, that the structure of -- of the congregations is much looser. However, as -- as these congregations continue to go on, as -- as time lapses and communities grow, there is a need for more and more structuring.

NEESON: And with that structure came a power struggle. Who would emerge as the new face of Christianity?

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NEESON (voice-over): As Christian communities took hold around the Mediterranean, women were critical in spreading and nurturing the new faith. But now, at the beginning of the second century, a hierarchy develops. And its face is male.

EHRMAN: Eventually, Christianity came to oppress women and to silence women. And, so, throughout history, of course, Christianity has been known as a male religion, in that only the leader -- only the men can be leaders of the churches. Only men can be the priests or the pastors or the pope.

But, in the early days, Christianity was probably much more in tune with women's needs and the possibility of women playing leadership roles in the churches.

LIEU: It is a man's world. And it's a world when it's quite often difficult to -- to capture the glimpses of women, and to capture the glimpses of -- of what women themselves felt. On the whole, women don't write in this world. They don't leave records of what they are doing.

NEESON: As a result, the few surviving documents we have are written by men of the church, who drafted blueprints for church life in works such as the Didache.

PFANN: The Didache, for example, which is a composition that is titled "The Teaching" -- didache means teaching -- "The Teaching of the 12 Apostles to the Gentiles." And this is meant to be part of the legacy of the Jerusalem and Jewish Christian community to help Gentile Christian communities structure themselves. NEESON: Locked in the library of the Greek Orthodox patriarch in Jerusalem is the single surviving copy of the Didache. Written about 100 A.D., it is a type of how-to manual for early Christians that provides practical advice, how to worship, pray, baptize.

PFANN: How do you baptize? Do you immerse, or do you sprinkle? What do you do if there's not enough water? How do you handle this situation? How do you celebrate communion? How do you break the bread? What should you say when you have the lord's supper? Very practical advice.

The Didache provided structure for the earliest Christians. And with structure came power. And with that power came the final foundation stone of what we recognize today as the church, the authority to define what is sacred scripture and what is heresy.

LEVINE: Surely, by the end of the first century, the letters of Paul have been collected. The Gospels Matthew, Mark, Luke and John, and likely other gospels, as well, had been written. But it would take another several centuries before the canon of the church, as we know it today, finally took shape.

EHRMAN: Different Christian communities had different gospels that they -- that they read during their worship services. Eventually, as it turned out, of course, only four Gospels made it into the New Testament. And scholars are fairly convinced that these four, in fact, are the four earliest Gospels.

NEESON: With dozens of other gospels circulating, how did church leaders ensure the survival of the Gospels of Matthew, Mark, Luke and John?

EHRMAN: It is true that church leaders discouraged the reading of these other books, and they -- they didn't allow them to be read in their church services.

But they didn't burn these other books. The way that you would prevent a book from being circulated in the ancient world was simply by not copying it. So, the way to destroy a book was simply not to reproduce it. And that's probably what happened to most of the gospels that didn't make it into the New Testament.

NEESON: Armed with a hierarchy, a distinct set of beliefs and rituals, and canon of sacred texts, the Christian church not only had structure, but had power, a clear and present danger to the Roman Empire.

Christianity, attracting millions of followers, growing in its influence, extending its reach, had to be wiped out.

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NEESON: Mighty Rome was in trouble, threatened by warlike tribes and ruled by two rival emperors. On October 28 in 312 AD, Emperors Maxentius and Constantine and their armies met on the banks of the Tiber River near the Milvian Bridge to fight for total control of the empire.

Though Constantine's soldiers were outnumbered four to one, he had a secret weapon.

EHRMAN: Before the battle, he had a vision in which he saw a sign of the cross in the sky and the words written over it that said, "By this, conquer." He didn't know what this meant so he called in some dream interpreters and they told him this meant that it was the cross of Christ that would allow him to be victorious.

And so he arranged to have the image of the cross painted on the shields of all of his warriors.

NEESON: Constantine vowed to convert to Christianity if he won the battle and for centuries, his victory was seen as a turning point for Christianity. But did Constantine really convert to the faith his empire had tried to destroy?

EHRMAN: Some historians have doubted whether Constantine actually converted in the year 312. And it's true that there's some evidence that he retained a devotion to some of the Roman gods.

Even after allegedly converting, for example, he minted coins in which he had a picture of the Sun God. The inscription on the coin was "Sol Invictus," which means the unconquerable sun, a reference to the sun god, who, in fact, was over all.

And so was he really a worshiper of the God of Jesus or was he a worshiper of the Sun God?

O'COLLINS: By that time, of course, Christians ran to millions. And I suppose Constantine thought, "If you can't beat them, join them."

And I think with his mother, too, he thought, "Well, this is true."

NEESON: Constantine had an influential mother, Helena, a devoted Christian. She traveled to the Holy Land and located the most important sites from the Christian story, building great shrines that remain among the holiest Christian places today.

O'COLLINS: She was a very noble lady and she led the building program in the Holy Land to have the Church of the Holy Sepulchre built, where Jesus was buried and rose from the dead, and, also, a church built to honor the giving of the Our Father, the Lord's Prayer.

She had a building program there, that she had the money and his support.

NEESON: Constantine also found in her faith something that would redeem him. O'COLLINS: He knew Christian faith very well and he knew that baptism remitted all your sins. And he had quite a bit of blood on his hands. He wasn't the head of the Roman Empire from being Mr. Nice Emperor.

NEESON: Indeed, Constantine was ruthless. He killed his son, his wife, and several relatives. He had persecuted and tortured Christians. Yet, with numbers in the millions, he knew they were crucial to keeping his fragile empire together. So he made Christianity legal in the year 313. That ended decades of brutal persecution. But it marked fierce internal battles in the church, the biggest of which went to the heart of Christianity.

PFANN: Now, while the church was persecuted as an illegal religion and underground, there was only so much work that it could do to normalize what would be the heart of Christian teaching about the nature of God, about the nature of Jesus, about relationships within the church.

NEESON: But once Constantine legalized the church, long-standing doctrinal questions broke into the open, the biggest of them going to the core of Christian belief: was Jesus truly the son of God or just a wise man?

Was Jesus truly the son of God or just a wise man?

EHRMAN: Constantine didn't care which side won this debate. Constantine wanted a unified Christianity because he wanted a unified empire. And he wanted to use Christianity to help him unify his culturally-diverse empire.

So he wanted Christians throughout the empire to agree on major theological issues.

NEESON: In the year 325 AD, Constantine called the world's bishops to the small town of Nicea outside the imperial city of Byzantium to grapple with the essence of Christian belief.

PFANN: What we now call the Nicean Creed -- "I believe in God, the Father Almighty, creator of heaven and earth" -- those tenets of faith come down from the fourth century and are still the bottom line of Christian teaching today.

NEESON: And the heart of the Nicean Creed and Christian faith is the Jesus was both God and man.

GRIFFITH-JONES: The earliest communities were already giving Jesus the worship that could only be given to God. This is happening within 30 years of Jesus' death. But to find a philosophical language in which to say it, in which to formulate it, that took 300 years.

EHRMAN: The Council of Nicea was not called in order to decide whether Jesus was divine. It was called in order to decide in what way is Jesus divine. Is Jesus a secondary deity, a subordinate deity or, in fact, is he equal with God the Father. And the side that won out was the side that declared that Jesus was equal with God the Father, that he had always been God.

NEESON: Beyond questions of dogma, however, Constantine's Nicean Council was also a major political turning point for the church.

EHRMAN: Constantine declared Christianity a legal religion and he stopped the persecution. But it's not correct to say that Constantine made Christianity the official Roman religion. In fact, he didn't make it the official religion. He did make it a favored religion and he started giving lands to Christian bishops and supplying funds for the building of churches and so forth. This made it a very popular thing to become a Christian, especially to become a Christian leader. So from going from being a persecuted small sect, it turned into an important religion that was favored by the emperor.

MEYER: Ultimately, the decision is made by some kind of a vote. Ultimately, it has to do with power and with politics. And that's how people decide who is on the inside and has the right way of thinking, and who is on the outside, as the other, and should be excluded as a heretic.

NEESON: Some 300 years after Jesus, Christianity was now the dominant religion of Europe and it would spread around the world.

As the Roman Empire crumbled under assault by barbarians, Christianity rose to become an empire of faith.

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NEESON: In the span of three centuries, the life and death of a Jewish rabbi from Nazareth had become the basis of the favored religion of the Roman Empire and gospel to millions, an astounding development that still fascinates and confounds even the experts.

FREUND: It's interesting that one single Jew becomes the focus of the devotions of a whole people, while -- you know, there were many other Jews who were -- who had also been crucified and many of them were also known as Messiahs, in the same time period. None of them have the following. So the big question is, why Jesus? Why did he get that type of following? And that's the real quest of people, you know, who work out in the field and archaeology, is trying to figure out why Jesus?

NEESON: Little wonder that the most popular explanation over the ages was that this all had to be the work of God.

But historians don't work from divine theories.

EHRMAN: The historian can only look at what did happen in time and space and what we can say with some certainty is that the early followers of Jesus came to believe that Jesus had been raised from the dead and they were able to convince other people that Jesus was raised from the dead.

NEESON: Perhaps it was just the right faith at the right time, with a world ready for a messiah who offered universal salvation. GRIFFITH-JONES: At a time of instability in the Roman Empire and emerging danger in the Roman Empire, an overextended empire, incredulity clearly in the traditional gods of the Roman Empire, and Christianity offering something that appeared to be utterly and beautifully coherent about everything from the smallest detail of your daily life and the community around you, through to eternity. This is very compelling.

NEESON: Some would say it was ultimately power politics, both divide and earthly, with an emperor recognizing the power of the people and their faith.

SCHIFFMAN: It seems to me that what really made the difference in turning what was the whole Greco-Roman world into Christian was essentially the Roman government decision. That is to say Christianity was spreading and it was getting bigger and bigger. But without that decision on Constantine's part, what we know of as Christianity as a world religion, probably wouldn't have taken place.

NEESON: In the end, the story must always return to the beginning, to a single man from the Galilee, and a message so powerful that it moved his unlikely disciples to great things.

LEVINE: It's sometimes suggested that a group of fishermen from the Galilee would be incapable of establishing a worldwide religion, but that's simply our own modern skepticism. After all, Abraham, a single man from Ur of the Chaldees, managed to do so and Muhammad, a single individual, managed to do so.

The human spirit is remarkable, if people simply put their mind to accomplishing what they feel God calls them to do.

NEESON: Whatever accounts for Christianity's success, the debates, over what the faith in Jesus is and what organized religion should be, are far from settled.

MEYER: In the beginning of Christianity, there is diversity. There are different points of view, different interpretations of Jesus, different ways of understanding God and the world. And in the beginning, there is no Orthodoxy and heresy.

NEESON: But that situation did not last for long. And much of the first 300 years of Christianity and beyond were spent defining that faith.

MEYER: The struggle regarding orthodoxy and heresy never comes to an end and these battles about truth and inclusion and exclusion are with us to the present day.

PFANN: Sometimes we say if we could just get back to New Testament Christianity, then the church would live in unity. But in reality, when we look at the pages of the New Testament, we find that from the very beginning, diversity characterized the earliest believers, whether they were Jewish Christians or gentile Christians. The Christian message and the Christian church has always lived in this tension of diversity. GRIFFITH-JONES: And the church has gradually and slowly built up a fuller and fuller understanding of what it is to be human in the image of God, trying to be honest to the Jesus who walked in Galilee, and delivered the sermon of the mount, and, also, trying to be honest to the lives we lead in the 21st century. And that will always be in tension, always.

NEESON: Christianity has survived many powerful attempts to kill it off. And today, many of the issues that occupied the first Christians are once again causing us to debate, challenge, and to believe or not, 2,000 years after Jesus.

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